Novel Approach Found to View Inner Workings of Viruses
|Researchers at NIAMS have developed a new way to see structures within viruses that were not clearly seen before.
Since the discovery of the microscope, scientists have tried to visualize smaller and smaller structures to provide insights into the inner workings of human cells, bacteria and viruses. Now, researchers at NIAMS have developed a new way to see structures within viruses that were not clearly seen before. Their findings were reported in the Jan. 13 issue of Science.
Cryo-electron microscopy (cryo-EM) is a technique that allows scientists to image very small particles such as structures on the surface of viruses. This method has been useful in helping researchers understand how vaccines work. But, despite the success of cryo-EM, scientists have been unable to clearly visualize structures inside of viruses because radiation is used to image them. “With lower doses of radiation, it is not possible to see inside the organism,” said lead author Dr. Alasdair Steven of NIAMS’s Laboratory of Structural Biology Research. “However, higher doses of radiation damage the virus, destroying the very structures that we would like to view.”
Working in collaboration with the group of Dr. Lindsay Black at the University of Maryland Medical School, Baltimore, Steven and his team were able to turn the problem of radiation damage into an asset. Viruses, one of the simplest life forms, are made up of nucleic acids (DNA or RNA) and the proteins encoded by the nucleic acid instruction manual. The researchers realized that proteins inside the virus are more sensitive to damage than DNA.
32 Million Americans Have Autoantibodies That Target Their Own Tissues
More than 32 million people in the United States have autoantibodies, which are proteins made by the immune system that target the body’s tissues and define a condition known as autoimmunity, a study shows. The first nationally representative sample looking at the prevalence of the most common type of autoantibody, known as antinuclear antibodies (ANA), found that the frequency of ANA is highest among women, older individuals and African Americans. The study was conducted by NIEHS. Researchers at the University of Florida also participated.
Earlier studies have shown that ANA can actually develop many years before the clinical appearance of autoimmune diseases such as type 1 diabetes, lupus and rheumatoid arthritis. ANA are frequently measured biomarkers for detecting autoimmune diseases, but the presence of autoantibodies does not necessarily mean a person will get an autoimmune disease. Other factors, including drugs, cancer and infections, are also known to cause autoantibodies in some people. The findings appeared online in the Jan. 11 issue of Arthritis and Rheumatism.
Vitamin D May Improve Bone Health in People Taking Anti-HIV Drug
Vitamin D may help prevent hormonal changes that can lead to bone loss among those being treated for HIV with the drug tenofovir, according to the results of an NIH network study of adolescents with HIV. The findings were published online in Clinical Infectious Diseases.
Tenofovir is widely used to treat HIV infection. However, the drug causes symptoms that resemble those of vitamin D deficiency, causing bones to lose calcium and reducing bone density. The study found that large monthly doses of vitamin D reduced blood levels of a hormone that stimulates calcium release from bones.
“What we’ve found suggests vitamin D could be used to counteract one of the major concerns about using tenofovir to treat HIV,” said Dr. Rohan Hazra of NICHD, which funds the networks. “People in their teens and twenties may be on anti-HIV treatment for decades to come, so finding a safe and inexpensive way to protect their long-term bone health would be a major advance.”
Cause of Rare Immune Disease ID’d
Investigators at NIH have identified a genetic mutation in three unrelated families that causes a rare immune disorder characterized by excessive and impaired immune function. Symptoms of this condition include immune deficiency, autoimmunity, inflammatory skin disorders and cold-induced hives, a condition known as cold urticaria.
The study, published in the online edition of the New England Journal of Medicine on Jan. 11, was led by Dr. Joshua Milner of NIAID and Dr. Daniel Kastner of NHGRI.
The mutation discovered occurs in a gene for phospholipase C-gamma2 (PLCG2), an enzyme involved in the activation of immune cells. The investigators have named the condition PLCG2-associated antibody deficiency and immune dysregulation, or PLAID.— compiled by Carla Garnett